Viscoelastic Tamponade Applied to the Ocular Surface for Enhanced Control of Gaseous Egress From the Anterior Chamber During Final Bubble Titration in DMEK Surgery: The "Polite" Burp.

PURPOSE: To present a novel technique for enhancing the surgeon's control over the volume of air or gas that is "burped" from the anterior chamber during final bubble and intraocular pressure (IOP) titration in Descemet membrane endothelial keratoplasty. METHODS: After ascertaining that the intracameral bubble is either too large and/or has rendered IOP too high, a bead of ophthalmic viscoelastic is applied to the ocular surface over a paracentesis incision, which is then depressed in the usual fashion to burp gas from the anterior chamber. RESULTS: The weight and viscosity of the viscoelastic create a tamponade that slows the egress of gas from the anterior chamber, thereby making it more controllable. CONCLUSIONS: If the bubble size or IOP needs to be reduced at the conclusion of the Descemet membrane endothelial keratoplasty procedure, application of ophthalmic viscoelastic over the paracentesis can enhance the surgeon's control over the volume of gas burped from the anterior chamber, thereby reducing the tendency to swing between a bubble that is too large or too small.

Partitioning an Artificial Anterior Chamber With a Latex Diaphragm to Simulate Anterior and Posterior Segment Pressure Dynamics: The "DMEK Practice Stage," Where Surgeons Can Rehearse the "DMEK Dance".

PURPOSE: To present a novel apparatus for simulating the anterior and posterior segment pressure dynamics involved in executing Descemet membrane endothelial keratoplasty (DMEK) surgery when using a chamber-shallowing technique. METHODS: An artificial anterior chamber (AAC), 18-mm trephine, latex glove, two 3-mL syringes, and one donor cornea comprising an intact corneoscleral cap from which a DMEK tissue was peeled and punched are required for the model. After making the corneal incisions with the corneoscleral cap mounted on the AAC in the usual fashion, the corneoscleral cap is remounted onto the dried AAC over an 18-mm latex diaphragm. The space between the latex diaphragm and the cornea is filled with saline to pressurize the anterior chamber, and the posterior segment is pressurized with air from a syringe. The resulting apparatus comprises a posterior segment and anterior chamber that exert pressure on each other by way of a distensible latex diaphragm. RESULTS: A novice and experienced DMEK surgeon and 2 eye bank technicians were able to assemble the apparatus and perform the routine steps of a DMEK procedure, including maneuvers that require shallowing the anterior chamber and lowering its pressure. Only one cornea was required per apparatus. CONCLUSIONS: We present a novel in vitro model of the human eye that more closely mimics the anterior and posterior segment pressure dynamics of in vivo DMEK surgery than average human and animal cadaveric globes. The model is easy to assemble, inexpensive, and applicable to a range of teaching environments.

Clinical Experience With PROSE Fitting: Significance of Diagnosis and Age.

OBJECTIVE: To compare ease of adoption of the BostonSight Prosthetic Replacement of the Ocular Surface Ecosystem device, a custom-fit scleral lens, by patients in different age and diagnosis groups. METHODS: In this prospective study, patients were categorized by age as younger than 60 or 60 years and older and by diagnosis as corneal irregularity (CI) or ocular surface disease (OSD). Ease of adoption of the scleral device was assessed by (1) number of devices and visits required to complete the fitting process, (2) time needed for device insertion and removal, (3) adaptation to the device, as assessed by daily wear time and by time needed to achieve full-time wear (defined as 8 hours per day), and (4) patients' subjective rating of ease of device insertion and removal. The length of the fitting process was also assessed. RESULTS: There was no significant difference in the number of devices and visits needed between age group younger than 60 and age group of 60 and older or between CI and OSD groups. Patients in all groups achieved full-time wear in less than 2 weeks. Average wear time per week did not differ significantly between age or diagnosis groups. Similarly, the time needed for daily insertion and removal during the fitting period, as well as patients' subjective rating of ease of device insertion and removal, did not differ between age or diagnosis categories. The length of the fitting process was significantly longer in the OSD group compared with the CI group (P<0.001); however, factors not related to ease of adoption of the scleral device may be responsible for this difference. CONCLUSIONS: Patients in both younger and older patient groups adopted the use of a scleral device with equal ease, as did patients in the CI and OSD diagnosis groups.

Corneal keloid: report of natural history and outcome of surgical management in two cases.

PURPOSE: To report the natural history and the outcome after the surgical management of 2 cases of corneal keloids. METHODS: Two male patients, 21 and 24 years old, with a history of corneal opacity for 5 and 17 years, respectively, with no history of an ocular trauma were studied. RESULTS: The first patient initially underwent a superficial keratectomy (SK), after which the corneal opacification recurred. He subsequently underwent 2 SK procedures combined with phototherapeutic keratectomy and mitomycin C, followed by a femtosecond laser-assisted deep anterior lamellar keratoplasty. The second patient underwent a bilateral SK followed by a penetrating keratoplasty in the left eye with the rapid recurrence of the lesion. The patient subsequently underwent an implantation of a Boston type 1 keratoprosthesis in the right eye, with a favorable outcome. The histopathologic features of both excised corneal specimens were consistent with the diagnosis of a corneal keloid. CONCLUSIONS: Corneal keloids recur after SK and phototherapeutic keratectomy, indicating that keratoplasty procedures may be more effective than keratectomy procedures in their management. However, corneal keloids may recur even after a penetrating keratoplasty, in which case keratoprosthesis implantation represents a viable option for visual rehabilitation.